FAQ

  • Where is my log file? Where is my config.ini file? Read this explanation.!
  • I can't find all those files you are talking about. A big contributing factor to this problem is that Windows default settings hides system files, and also by default, don't show file extensions. These settings can be changed however. In XP go to My Computer ->Tools -> Folder Options -View. Mark "Show hidden files and folders" and untick the box "Hide extensionsfor known file types". Other versions of Windows are similar, but may not be exactly like this. Now you should find the files we talked about in the previous paragraph. 
  • I have a problem so I reinstalled - but that did not help. Try this approach instead.
  • I get a lot of error messages when starting OpenCPN from the Linux commandline.    Messages like (opencpn:8979): Gdk-CRITICAL **: IA__gdk_drawable_get_size: assertion `GDK_IS_DRAWABLE (drawable)' failed
    (opencpn:8979): Gdk-CRITICAL **: IA__gdk_drawable_get_depth: assertion `GDK_IS_DRAWABLE (drawable)' failed
    Error opening coefficient file
    (opencpn:8979): Gdk-CRITICAL **: IA__gdk_window_get_origin: assertion `GDK_IS_WINDOW (window)' failed
    are quite normal an has nothing to do with OpenCPN. Just ignore them.                     
  • What are all those 'U' things all over my chart?

The feature being rendered is S57 Text relating to 'M_QUAL'.

This is a meta-object describing the quality of data shown. The Attribute of interest is CATZOC, or "Category of Zone of Confidence". The value on most US ENC's is "6", or "un-assessed". Thus, the 'U'.

You can turn this symbol off in OpenCPN by de-selecting the box next to M_QUAL in 'Tool Box' / 'Vector Charts' tab 'Mariners Standard' selection list box.
Unticking the box "Meta Objects" also hides the "U" symbols.

To learn the acronyms used in this application search the S57 'Object and Attribute' catalog at: http://www.s-57.com/

  • I have routes and way points in Sea Clear and I would like to import them into OpenCPN. Can I do it?

Yes. I had originally created and maintained all my routes and waypoints in SeaClear, exported them, loaded them into GPSUtility (for Windows) and saved them as text files.

To import into OpenCPN  I opened all my text files (routes and waypoints) with GPSUtility, saved that out as one big gpx file, and loaded it into OpenCPN. Works like a champ.

I've edited them and saved them back out as GPX files with no trouble.

Individual routes can be edited and saved in appropriately named GPX files.

  • Whenever I try to open a particular chart OpenCPN crashes. What's going on?

Chances are the chart file is corrupted. Note the name and number of the suspect chart and replace it with a fresh download. Read the log file that may contain relevant information refarding the chart. Sometimes the bad chart blocks OpenCPN from restarting. Follow these
instructions.


  • OpenCPN and Great Circle Navigation

Raster charts display bearings and headings as straight, measurable lines on the chart. Similarly, Vector ENC's are rendered as Mercator projections in OpenCPN and most other ECS's for the same reason.

For typical coastal navigation, errors which occur using rhumb line instead of great circle calculations are small for the distances usually covered by one chart.

Mercator Charts and Mercator navigation is the standard for most navigational purposes. Other terms used instead of "Mercator Sailing" is "Loxodrome Sailing" or "Rhumb Line Sailing".

OpenCPN uses Mercator Sailing and cannot directly display Great Circles, but through GPX route import , Great Circle Routes can be used as explained on Planning Data page in the wiki.

This article is in not complete. You are welcome to assist in its construction by editing it as well. Everyone is allowed to edit after creating and account and/or logging in.